South Korea's KSLV-1 (a.k.a. Naro-1) failed 137 seconds after lift-off from the Naro National Space Center on 10 June 2010, 0801 UTC. Lift-off was nominal. However, all telemetry was lost as the rocket had reached the altitude of 70 km, Science Minister Ahn Byong-man said, "looking from the bright flash seen on the camera mounted on the top of the rocket, it appears the Naro exploded in flight during the first-stage ignition," he told a briefing.

The rocket's payload, the Science and Technology Satellite 2B (STSAT 2B), was also destroyed. The spacecraft had been due to separate from the rocket at an altitude of 302 km and to deploy its solar panels about nine minutes after blast-off.

The Korea Aerospace Research Institute (KARI) meanwhile confirmed that the debris has fallen in the waters off the southern coast of Jeju Island. Owing to the loss of all links with the rocket, its onboard flight termination system could not be activated by ground control.

The first stage was built by Russia's Khrunichev Space Center. The company said a joint failure review board will be set up by Korean and Russian specialists to investigate the causes. It is yet unknown whether the mishap was actually caused by a first stage malfunction as other explanations, such as a problem with the second stage's payload fairing during ascent, so far could not been ruled out.